turns out we are using static variables to register entries in
global registries, and these variables are not directly referenced,
so linker just drops them when linking the executables or shared
libraries. to address this problem, we just link the whole archive.
another option would be create a linker script or pass
--undefined=<symbol> to linker. neither of them is straightforward.
a helper function is introduced to do this, as we cannot use CMake
3.24 as yet.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
